Orbital perforator

ABSTRACT

A novel perforating apparatus is provided in which a series of sequentially, orbitally moving perforating segments are applied with vertical and horizontal compronents of movement to a work piece so that each of a plurality of individual perforating elements mounted on the segments reciprocates in a direction perpendicular to the upper face of the work piece throughout its stroke.

0 United States Patent 11 1 1111 3,747,447 Wisner 1 July 24, 1973 54] ORBITAL PERFORATOR 2,142,728 1/1939 Kienzle 83/600 x 3,369,435 2/1968 Boultinghouse 83/660 X [75] Inventor' L318 1,690,410 ll/l928 Hudson 83/337 73 Assign; The Cdotex Corporation Tampa, 1,931,979 10/1933 Chandler 83/600 X Fla 1,750,708 3/1930 Edwards 83/347 X [22] Filed: 1971 Primary ExaminerJ. M. Meister [2]] Appl' 137,202 Att0rney.lames W. (irace 52 us. Cl 83/2, 83/327, 83/337, [57] ABSTRACT 83/660 A novel perforating apparatus is provided in which a [51] Int. Cl. G26! 1/24 series of sequentially, orbitally moving perforating seg- [58] Field of Search 87/327, 328, 2, 660, ments are applied with vertical and horizontal compro- 87/30, 32, 337 nents of movement to a work piece so that each of a plurality of individual perforating elements mounted on [56] References Cited the segments reciprocates in a direction perpendicular UNITED STATES pATEN-TS to the upper face of the work piece throughout its 3,073,826- 3/1963 Shively 83/660 x Stroke 4 Claims, 9 Drawing Figures PAIENIEDJUL24 m5 3. 747. 447

SHEET 1 BF 2 INVENTOR. LOUIS M.WISNER [U baw ATTORNEY.

Pmmiuwm' 3.747.441

SHEET 2 [IF 2 16.5 OR ART) F'IG.6

INVENTOR. LOUIS M.WISNER ORBITAL PERFORATOR BACKGROUND OF THE INVENTION 1. Field of the Invention:

The novel perforating apparatus of the invention is used to perforate panels which are generally greater than one-half inch in thickness and of almost any width or length. The width and length limitations of the panel are determined by the dimensions desired by the manufacturer in view of the type of manufacturing apparatus preferred. Although preforated panels find use in many fields, the present invention has been developed primarily for use in perforating fibrous acoustical panels. While the principle of operation of the perforating apparatus of the invention does not limit its use to sheets of any given thickness, sheets of paper, cardboard or other very thin material can be more easily perforated by a porcupine-like roll.

2. Description of the Prior Art:

' In the production of perforated panels for acoustical treatment in buildings, there are generally two types of perforating apparatus in use. These are the roll perforator and the vertical stroke press.

The roll perforator consists of a driven cylindrical roll which has a large number perforating elements projecting outwardly from its surface. The axis of rotation of the roll is perpendicular to the direction of travel of the panel to be perforated. As the panel or work piece is carried on a conveyor in tangential relation with the roll, the perforating elements penetrate the surface of the panel to produce a perforated surface. For shallow penetrations a roll perforator is adequate. However, as the length of the penetrating elements become greater to achieve a deeper perforation, the elements tend to create holes which are elongated in the direction of travel of the panel and are not accurate reporductions of the shape of the perforating elements. In extreme cases, the holes become slashed trenches. Since a clean round hole seems to be preferred, the roll perforator is limited to penetrations less than inch in depth.

When it is desired to use the perforated panel as an acoustical unit to absorb sound, the limitations imposed by the roll perforator become more serious. The depth of penetration of the pins of a roll perforator is generally limited to about /32 inches in order to have an acceptable appearance. An increase in depth beyond this amount results in the slashed trenches previously referred to. In one pattern of holes with this depth, an NRC of 47 was achieved. NRC is a standard unit of sound absorption measured by tests well known in the acoustical art and used by architects and acoustical product manufacturers to compare the sound absorption efficiency of various products. In contrast to this NRC figure of47, a similar pattern of holes in comparable material with a depth of penetration of /32 inches resulted in an NRC of 60. This increase in sound absorption efficiency can be achiev'edwithout loss of hole definition when the apparatus of the invention is used instead of the more conventional roll perforator.

The vertical stroke press consists of a plate which has a number of penetrating elements. extending downwardly from its flat surface. The plate is reciprocated and caused to penetrate the surface of a panel to achieve a perforated effect. However, the vertical stroke press, while it produces holes with an outline which accurately reproduces the shape of the perforating element, does not permit as fast an operation as the roll perforator. In fact, the speed of production of perforated panels is often slowed to an economically detrimental rate.

,SUMMARY OF THE INVENTION To provide the line-speed of the roll perforator with the accuracy and clean perforating action of the vertical stroke press, the present invention provides an apparatus in which a series of orbitally moving segments with extending perforating elements perforate the work piece with a component of motion perpendicular to the face of the work piece and a horizontal component of motion equal to the horizontal line speed of the work being manufactured.

It is an object of the present invention to provide a novel perforating apparatus which perforates panels with holes which are accurate reproductions of the shape of the perforating elements.

It is another object of the present invention to provide a novel perforating apparatus which is fast in operation and does not unduly limit the line speed of the panel forming apparatus.

It is yet another object of the present invention to provide a novel perforating apparatus which has perforating elements mounted on easily replaceable segments.

It is still a further object of the invention to provide a novel perforating apparatus which is capable of producing holes of greater depth than some previously available types of perforators.

Other objects and advantages of the invention will become apparent to those skilled in the art when the following description is considered in conjunction with the accompanying drawing in which like numerals indicate like elements and in which:

FIG. 1 is a side elevational view of the orbital perforating apparatus of the invention;

FIG. 2 is an enlarged elevational cross-sectional view of a portion of the orbital perforating apparatus shown in FIG. 1,

FIG. 3 is an elevational view of the arrangement of the perforating segments looking upwardly and perpendiculafly at the apparatus shown in FIG. 2 with the lower conveyor and the work piece eliminated;

FIG. 4 is a side elevational view of the perforating segments taken along line 4-4 of FIG. 3.

FIG. 5 is a top plan view of a work piece or panel perforated by a prior art roll perforator;

FIG. 6, 7 and 8 are top plan views of panels having patterns perforated thereon by the orbital perforating apparatus ofthe invention; and

FIG. 9 is a side elevational view of an alternative arrangement of the perforating wheel of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings and particularly FIG. 1, there is shown a panel 12 supported upon and carried by a conveyor 15 which runs under an orbital perforating mechanism on roll 18.

Panel 12 may be a conventional fibrous acoustical panel made from vegetable fibers on a modified Fourdrinier apparatus. If desired, it may be a mineral fiber panel with a resin binder. Each of these types of panels is commercially available and the processes for their manufacture generally known. The panels are conventionally made in thicknesses from v. inch to three inches and about four feet in width as a continuous mat in the wet or Fourdrinier process. The panels may, if desired, be made in preformed lengths in a press. In either process, the prepared panel 12 is carried to and put on a belt of conveyor 15. Belt 20 may be made of interconnected metal segments or heavy duty reinforced fabric.

Belt 20 is stretched between two spaced drums 22 and 23 journalled on a supporting framework 25. Drum 22 is driven at a preselected rotational speed by a sprocket and chain drive 27 connected to a drive motor 28. The drive mechanism 27, 28 establishes the linear speed of the belt 20. A series of idler rolls 30 are journalled along the upper section of framework 25 to support the conveyor belt 20 in a horizontal plane when it carries panel 12 through the perforating operation.

To the left of conveyor 15 is shown a take off conveyor which carriesthe perforated panel 12 to further fabricating apparatus, such as paint spray equipment, routers, cutters and packaging stations (not shown).

Orbital perforating mechanism 18 is mounted on a support by means of a journal or pillow block 37. A sprocket and chain drive 39 is connected to the axle 41 of perforating mechanism 18 and to a drive motor 43. The rotational speed of drive motor 43 is adjusted so that the peripheral speed of the perforating mechanism 18 is slightly greater than the linear speed of conveyor belt 20. The other end of axle 41 is journalled in similar manner on a support (not shown).

In the preferred embodiment perforating mechanism 18 comprises the control axle 41 as .part of a central hub 45. Spaced circular rings 48 and 49 are connected to the hub 45 by spokes 50. Each ring 48 and 49 is located near a respective end of axle 41 and they are spaced a distance about equal to the width of the conveyor l5. Perforating segments span the distance between the spaced rings 48 and 49. Each of the perforating segments 55 is connected by bearings 56 to rings 48 and 49 by its own rod 57 around which the segment is free to pivot or rotate.

In effect, the perforating mechanism 18 may be likened to a ferris wheel or squirrel cage with the outer spaced rings which support the seats being connected by spokes to a central hubaround which the wheel rotates. The perforating segments of this invention 55 correspond to the seats of the ferris wheel, and it will be recalled that the seats are connected to individual axles which allow the seat to remain in a horizontal level condition even as the ferris wheel rotates. The segments 55 orbit around the centralaxle 41 of the perforating mechanism and stay in a horizontal position because their journal 56 permits rods 57 to rotate within the journals.

To prevent excessive oscillatory motion of segments 55 a damper 59 is provided. Damper 59 may be merely a spring and set screw arrangement, as shown.

Each of perforating segments 55 has a large number of perforating elements 60 extending outwardly perpendicularly from the lower face of the segment. The perforating elements 60 may be hardened nails or short pieces of wire and are embedded in a layer 62 of epoxy resin which holds the elements in place. In one model, perforating elements were 17 gage nails. A backing plate 65 of thin metal forms a firm support'for the layer 62 of resin and provides a means for the connection of journal bearings 56 to the segments. As may be realized, the shape of some or all of the perforating elements may be elongated bosses capable of producing fissures rather than narrow holes.

The number and placement of perforating elements 60 is determined by the desired pattern of holes to be perforated. If a hole pattern of a specific design is preferred, the number and positioning of the perforating elements is thereby fixed.

It will be noted that the leading and trailing edges of each perforating segment has offset projections 74 and indentations 75. The projection 74 of one segment fits into the indentation 75 of a following segment. The purpose of this arrangement is to provide a pattern in which the perforations appear to be uniform over the entire surface of the panel. There is no single straight line without perforations to give an interrupted appearance to the pattern.

The segments 55 may be of any width but it has been found that a width of about three inches is practical. Segment 55 should be as thin as practicably possible so that the two adjacent segments will not bind as one is emerging from the surface of the panel and the next adjacent one is moving downwardly.

The operation of the orbital perforating apparatus will be explained with reference to FIGS. 1 4 of the drawings.

Panel 12, which is to be perforated, is carried by belt 20 under the perforating mechanism 18. The line speed of the conveyor may be set in relation to the actual manufacturing conditions for the selected panel. In this example, the conveyor was driven by motor 28 at 132 linear feet per minute. The perforating mechanism 18 was rotated by motor 43 and chain drive 39 at a peripheral speed of 164 linear feet per minute. The peripheral speed of the perforator wheel 18 must be slightly greater than the line speed of the conveyor because the tip ends of the perforating pins have a vertical and a horizontal component of motion. While the horizontal component of motion must be exactly the same linear speed as the panel, because the pins move vertically perpendicular to the face of the panel, a vertical component of movement must be accounted for. Thus, the peripheral speed of the perforating wheel 18 must be increased with respect to the line speed of the panel. In

effect, the pins travel in an are which is slightly longer than the linear distance travelled by the panel 12.

As the leading edge of panel 12 approaches the bottom of perforating mechanism 18, one of the perforating segments 55 will move downwardly to contact the surface of panel 12. As the panel proceeds further under the nip between the perforating mechanism 18 and the conveyor the perforating segment moves to the left and downwardly to push the perforating elements 60 into the face of the panel 12. As the panel 12 continues to move to the left, the perforating segment 55 reaches its lowest position for the greatest depth of penetration of elements 60 into the panel 12. As panel 12 moves further to the left the corresponding perforating segment 55 moves forwardly and upwardly to withdraw perforating elements 60 from the panel 12 to leave holes which are accurate reproductions of the shape of the perforating elements.

During the time that one segment 55 is being raised to remove the pins from the holes in the perforated portion of the panel, a following segment 55 is being interfitted along the trailing edge of the withdrawing segment. The following segment acts as a hold down element so that the panel does not rise up off the conveyor. In conventional press type punching systems a separate hold down element is required. The absence of a hold down element in this case simplifies the apparatus.

FIGS. 5 and 6 illustrate patterns of holes 80 resulting from the prior art rotating perforator (FIG. 5) and from the orbital perforator of the invention. The holes 80 or perforations illustrated in FIG. 5 show the elongated modified-elliptical type of perforation which results when pins 60 are fixed in the outer peripheral area of a rotating drum and their depth of penetration approaches /32 inches. The pins tend to move in an are rather than have a movement perpendicular to the face of the panel.

The pin pattern as shown in FIG. 6 results from the action of the perforating apparatus of the invention and as can be seen, the holes are clean and accurately reflect the shape of a round pin. The holes have a depth of about 15/32 inches and, if desired, can be even deeper without distortion.

FIG. 7 and 8 illustrate alternative shapes for the holes. The holes 80 in FIG. 7 are tapered to present a narrower bottom than top. If FIG. 8, the holes 80 are square and tapered. If desired, some or all of the holes may be irregular fissures generated by bosses rather than pins.

The holes may go all the way through the panel or may only penetrate a short distance.

FIG. 9 draws an alternative structure for the perforating mechanism 18. In this variation the perforating segments 55 are pivotally connected to rods 57 by bearings 56. Spaced pins or projections 90 and 91 are welded to the wheel 48 and cooperate with a rearwardly extending pin 95 connected to bearing 56 as shown with respect to one of the segments 55.

As the perforating mechanism 18 rotates the segment 55 is carried around and its rotational movement is held within a controlled angle. In this way the segments 55 do not oscillate as much as in the case of the arrangement of FIG. 1. It should be realized that the segment 55 should be in its horizontal position as it is applied to the face of panel 12. If the cage is rotating rapidly, the segments 55 have a tendency to oscillate in a small arc around their axles. The amount of such oscillation is much reduced in the configuration of FIG. 9.

An alternative structure for perforating mechanism 18 may be made if ring 48 and 49 are eliminated and the rods 57 are connected to the outer ends of spaced spokes 50. The remainder of the perforating mechanism 18 will be the same in structure.

In summary, the present invention comprises a novel orbital, perforating apparatus which has perforating segments mounted for orbital movement around a cage type structure. The perforating elements or pins have a vertical and a horizontal component of motion so that they enter the face of the panel or work piece perpendicularly to its face and continue along at the same horizontal speed as the panel so as to create clean accurately reproduced holes of sufficient depth as to result in an efficient sound absorber.

I claim: 1. An orbital perforating apparatus comprising: a conveyor of pre-selected width adapted to move at a preset linear rate of travel, and

a perforating mechanism having a rotational axle mounted a preset distance above said conveyor and having a plurality of perforating segments orbitally mounted around said rotational axle at fixed distances from said axle,

adjacent ones of said perforating segments having interfitting projections and indentations, each of said segments having a longitudinal pivot means mounted parallel to said rotational axle each of said segments further having a major longitudinal dimension such that each said segment substantially spans said pre-selected width of said conveyor each of said segments further having outwardly extending perforating elements adapted to move with a vertical and a horizontal component of move ment such that the rate of movement of said horizontal component of movement is approximately equal to said linear rate of travel of said conveyor.

2. An orbital perforating apparatus as recited in claim 1 in which said perforating mechanism comprises a centrally located, rotatable hub,

a plurality of pairs of spokes connected to said hub and extending outwardly therefrom,

said pairs of spokes being equiangularly separated from adjacent ones of said pairs,

a pair of spaced rings connected to the outer ends of said spokes,

rods connecting said rings,

and perforating segments journalled on said rods and adapted to remain in a generally horizontal position as the perforating mechanism rotates.

3. An orbital perforating apparatus as recited in claim 1 in which said perforating elements are arranged in the form of a predetermined pattern.

4. An orbital perforating mechanism as recited in claim 1 in which said perforating segments are in close adjacency such that when said perforating elements of one segment are being withdrawn from the face of a panel, said perforating elements of the next adjacent segment are entering the panel. 

1. An orbital perforating apparatus comprising: a conveyor of pre-selected width adapted to move at a preset linear rate of travel, and a perforating mechanism having a rotational axle mounted a preset distance above said conveyor and having a plurality of perforating segments orbitally mounted around said rotational axle at fixed distances from said axle, adjacent ones of said perforating segments having interfitting projections and indentations, each of said segments having a longitudinal pivot means mounted parallel to said rotational axle each of said segments further having a major longitudinal dimension such that each said segment substantially spans said pre-selected width of said conveyor each of said segments further having outwardly extending perforating elements adapted to move with a vertical and a horizontal component of movement such that the rate of movement of said horizontal component of movement is approximately equal to said linear rate of travel of said conveyor.
 2. An orbital perforating apparatus as recited in claim 1 in which said perforating mechanism comprises a centrally located, rotatable hub, a plurality of pairs of spokes connected to said hub and extending outwardly therefrom, said pairs of spokes being equiangularly separated from adjacent ones of said pairs, a pair of spaced rings connected to the outer ends of said spokes, rods connecting said rings, and perforating segments journalled on said rods and adapted to remain in a generally horizontal position as the perforating mechanism rotates.
 3. An orbital perforating apparatus as recited in claim 1 in which said perforating elements are arranged in the form of a predetermined pattern.
 4. An orbital perforating mechanism as recited in claim 1 in which said perforating segments are in close adjacency such that when said perforating elements of one segment are being withdrawn from the face of a panel, said perforating elements of the next adjacent segment are entering the panel. 